The present application claims the benefit under all applicable U.S. statutes, including 35 U.S.C. §119(e), to U.S. Provisional Application No. 60/680,381 Filed May 11, 2005, titled Apparatus for Converting Electromyographic Signals for Transferrance to a Personal Computer, in the names of Charles Dean Cyphery and Lance H. Butler, which provisional application claims benefit under all applicable U.S. statutes to U.S. application Ser. No. 10/504,301 filed Aug. 9, 2004, titled Comprehensive Neuromuscular Profiler, which application claims the benefit of priority to PCT Application No. PCT/US2004/22210.
This application incorporates by reference to U.S. Provisional Application. No. 60/680,381, U.S. application Ser. No. 10/504,301, and PCT/US2004/22210, as if all three applications were fully set forth herein.
Submitted herewith is a compact disc (1) which includes a computer listing of a program that may be used in connection with the apparatus disclosed herein. The compact disc contains one file, title “CNMP Source.11b”, which is the source code for the Comprehensive Neuromuscular Profiler invention (disclosed in U.S. application Ser. No. 10/504,301) and includes the LabVIEW program that is used to initialize the USB portion of the circuit board disclosed herein.
This application incorporates by reference the entire program and files on said compact disc.
This invention relates generally to a method and apparatus for monitoring the condition of muscles in a muscle group by the sensing and analysis of electromyographic (EMG) signals derived from electrodes positioned close to the muscle group and, more particularly, to an improved apparatus for converting EMG signals into data to be used with a personal computer so that the EMG data can be stored, reviewed, monitored and assessed.
The discovery of the presence of electromyographic (EMG) signals in the muscles of humans, and the change of these signals with muscle activity, spawned development of dedicated electronic devices and techniques for monitoring those signals for the evaluation of the muscles. The EMG signals given off by the muscles are relatively weak (on the order of microvolts) and it is important that the devices used to monitor and record the EMG signals do not introduce noise thereby making it impossible to interpret the signals.
Human musculature involves many hundreds of muscles in various muscle groups, which interact to provide skeletal support and movement. Recent developments in the field of EMG analysis have concentrated on the techniques and/or devices for monitoring the signals of a specific muscle or group of muscles. For example, U.S. Pat. No. 6,532,383 to Maloney et al. discloses an apparatus for detecting and interpreting EMG signals produced by the tongue; U.S. Pat. No. 6,411,843 to Zarychta discloses an apparatus particularly designed to detect EMG signals produced by the diaphragm; and U.S. Pat. No. 6,004,312 to Finneran et al. discloses an apparatus particularly designed to detect EMG signals produced by a muscle group (e.g., back muscles).
The size of the patient's muscle, range and dynamics of motion of the patient's muscle, the strength of the patient's muscles, and the electrical characteristics of the muscles provide information useful to a clinician making treatment decisions for a patient. The same information also may be useful to determine the existence, severity or cause of an injury and whether an injury is acute or chronic for purposes of determining questions of insurance or other liability.
Soft tissue injuries and pathology may occur in any area of the body and may include repetitive stress injuries, injuries to muscles, myofascial injuries, damage to vertebral disks, radiculopathy, and others. These injuries may be difficult to diagnose and hence may be difficult to treat properly.
The personal computer (PC) is currently the most popular form of computing device. The relatively inexpensive price, exceptional power, and availability of programs has led to the purchase and placement of a PC on virtually every desk in private industries, government agencies, research facilities, and universities. In fact, nearly every home in the U.S. has a PC or access to a PC through a school or a local library. With recent technological advancements, especially with the microprocessor, a PC can handle many of the functions that used to be reserved for work stations, or even main-frames.
Many standards have been developed expressly for the PC. For example, the SoundBlaster sound card standards, the PCI express bus, PCI bus, the AGP bus, and the universal serial bus (USB) interface, Firewire interface, etc. all were originally developed for use with the PC.
As with many technologies, the ability to input, record, display, analyze, and manipulate data with a PC is a useful feature. However, because of the complexity of the muscle structure, the number of electrodes/signals needed to acquire useful signals, and the general difficulty in obtaining reliable EMG signals in the first place (preferably in a non-invasive mode), obtaining a useful definition of the muscle activity in a reasonable amount of time and in an economical manner is still subject to current development.
Presently, there are no known devices that allow a practitioner to easily input and record EMG signals to a PC. At the very least, a dedicated apparatus is needed to convert and store the relatively weak EMG signals into a format usable by a clinician. The cost and complexity of such an apparatus are both relatively high. Accordingly, there is a need to quickly obtain EMG signals and store them on a PC for further analyzation and consideration.
The present invention is an apparatus consisting of a circuit board that allows a user to quickly and reliably acquire EMG signals and convert them into a format that allows the data to be stored on a PC for display and later manipulation. With higher speeds of operation and greater computing capacity, the capability for handling and operating upon a multiplicity of signals in a reasonable evaluation period has become feasible.
The present invention provides an apparatus for acquiring EMG signals from a patient and converting the EMG signals into a format for reading and storage on a personal computer. This apparatus includes an input for acquiring a plurality of EMG signals from sensors attached to a patient, a means for conditioning the acquired EMG signals, a means for converting the conditioned EMG signals to digital signals, a means for isolating the digital signals from the acquired signals, a means for temporarily storing the digital signals and a means for outputting the stored signals in a serial format for inputting into a personal computer.
The input for receiving the EMG signals includes a channel acquisition board which can handle inputs from a plurality of EMG sensor leads and a plurality of strain gauge inputs. Each EMG sensor lead consists of a single channel and has two sensors attached in order to measure the differential voltage. In the preferred embodiment the channel acquisition board consists of 18 channels for EMG sensor leads and six strain gauge input channels. These inputs are connected to the channel acquisition board preferably by a ribbon cable through two 40-pin connectors.
